1 //===- MCContext.h - Machine Code Context -----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCCONTEXT_H
11 #define LLVM_MC_MCCONTEXT_H
13 #include "llvm/MC/SectionKind.h"
14 #include "llvm/ADT/DenseMap.h"
15 #include "llvm/ADT/StringMap.h"
16 #include "llvm/Support/Allocator.h"
27 /// MCContext - Context object for machine code objects. This class owns all
28 /// of the sections that it creates.
31 MCContext(const MCContext&); // DO NOT IMPLEMENT
32 MCContext &operator=(const MCContext&); // DO NOT IMPLEMENT
34 /// The MCAsmInfo for this target.
37 /// Sections - Bindings of names to allocated sections.
38 StringMap<MCSection*> Sections;
40 /// Symbols - Bindings of names to symbols.
41 StringMap<MCSymbol*> Symbols;
43 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
45 unsigned NextUniqueID;
47 /// Allocator - Allocator object used for creating machine code objects.
49 /// We use a bump pointer allocator to avoid the need to track all allocated
51 BumpPtrAllocator Allocator;
53 void *MachOUniquingMap, *ELFUniquingMap, *COFFUniquingMap;
55 explicit MCContext(const MCAsmInfo &MAI);
58 const MCAsmInfo &getAsmInfo() const { return MAI; }
60 /// @name Symbol Managment
63 /// CreateTempSymbol - Create and return a new assembler temporary symbol
64 /// with a unique but unspecified name.
65 MCSymbol *CreateTempSymbol();
67 /// GetOrCreateSymbol - Lookup the symbol inside with the specified
68 /// @p Name. If it exists, return it. If not, create a forward
69 /// reference and return it.
71 /// @param Name - The symbol name, which must be unique across all symbols.
72 MCSymbol *GetOrCreateSymbol(StringRef Name);
73 MCSymbol *GetOrCreateSymbol(const Twine &Name);
75 /// LookupSymbol - Get the symbol for \p Name, or null.
76 MCSymbol *LookupSymbol(StringRef Name) const;
80 /// @name Section Managment
83 /// getMachOSection - Return the MCSection for the specified mach-o section.
84 /// This requires the operands to be valid.
85 const MCSectionMachO *getMachOSection(StringRef Segment,
87 unsigned TypeAndAttributes,
90 const MCSectionMachO *getMachOSection(StringRef Segment,
92 unsigned TypeAndAttributes,
94 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
97 const MCSection *getELFSection(StringRef Section, unsigned Type,
98 unsigned Flags, SectionKind Kind,
99 bool IsExplicit = false);
101 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics,
102 int Selection, SectionKind Kind);
104 const MCSection *getCOFFSection(StringRef Section, unsigned Characteristics,
106 return getCOFFSection (Section, Characteristics, 0, Kind);
112 void *Allocate(unsigned Size, unsigned Align = 8) {
113 return Allocator.Allocate(Size, Align);
115 void Deallocate(void *Ptr) {
119 } // end namespace llvm
121 // operator new and delete aren't allowed inside namespaces.
122 // The throw specifications are mandated by the standard.
123 /// @brief Placement new for using the MCContext's allocator.
125 /// This placement form of operator new uses the MCContext's allocator for
126 /// obtaining memory. It is a non-throwing new, which means that it returns
127 /// null on error. (If that is what the allocator does. The current does, so if
128 /// this ever changes, this operator will have to be changed, too.)
129 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
131 /// // Default alignment (16)
132 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
133 /// // Specific alignment
134 /// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
136 /// Please note that you cannot use delete on the pointer; it must be
137 /// deallocated using an explicit destructor call followed by
138 /// @c Context.Deallocate(Ptr).
140 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
141 /// @param C The MCContext that provides the allocator.
142 /// @param Alignment The alignment of the allocated memory (if the underlying
143 /// allocator supports it).
144 /// @return The allocated memory. Could be NULL.
145 inline void *operator new(size_t Bytes, llvm::MCContext &C,
146 size_t Alignment = 16) throw () {
147 return C.Allocate(Bytes, Alignment);
149 /// @brief Placement delete companion to the new above.
151 /// This operator is just a companion to the new above. There is no way of
152 /// invoking it directly; see the new operator for more details. This operator
153 /// is called implicitly by the compiler if a placement new expression using
154 /// the MCContext throws in the object constructor.
155 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
160 /// This placement form of operator new[] uses the MCContext's allocator for
161 /// obtaining memory. It is a non-throwing new[], which means that it returns
163 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
165 /// // Default alignment (16)
166 /// char *data = new (Context) char[10];
167 /// // Specific alignment
168 /// char *data = new (Context, 8) char[10];
170 /// Please note that you cannot use delete on the pointer; it must be
171 /// deallocated using an explicit destructor call followed by
172 /// @c Context.Deallocate(Ptr).
174 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
175 /// @param C The MCContext that provides the allocator.
176 /// @param Alignment The alignment of the allocated memory (if the underlying
177 /// allocator supports it).
178 /// @return The allocated memory. Could be NULL.
179 inline void *operator new[](size_t Bytes, llvm::MCContext& C,
180 size_t Alignment = 16) throw () {
181 return C.Allocate(Bytes, Alignment);
184 /// @brief Placement delete[] companion to the new[] above.
186 /// This operator is just a companion to the new[] above. There is no way of
187 /// invoking it directly; see the new[] operator for more details. This operator
188 /// is called implicitly by the compiler if a placement new[] expression using
189 /// the MCContext throws in the object constructor.
190 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {